In U.S. Pat. No. 3,270,478 to C. W. Attwood there is defined and described "space frame" construction and it is therein acknowledged that the general concept is known to have been contemplated before from the mere geometry viewpoint in U.S. Pat. No. 2,433,677 to H. H. Thomas. The Attwood patent discloses a space frame construction which may be described as being of generally pentahedron pyramidal modular construction comprising open channel chord members, open channel strut members, and fixture plates. The chord and strut members are of straight and equal lengths. The fixtures or connector plates are of a relative complex configuration comprising alternate flat and inclined surfaces for receiving the chord and strut members, with the chord members having the open face of their channel cross-section facing exteriorly of the pyramid form.
The Thomas patent discloses a roof structure comprising a plurality of pyramidal units each comprising straight framing members connected together, at the apex and the base corners, by junction members of general circular tubular cross-sectional shape having laterally directed screwed bosses to which screw couplings are connected.